scholarly journals Exploring Castellaniella defragrans Linalool (De)hydratase-Isomerase for Enzymatic Hydration of Alkenes

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2092 ◽  
Author(s):  
Matthias Engleder ◽  
Monika Müller ◽  
Iwona Kaluzna ◽  
Daniel Mink ◽  
Martin Schürmann ◽  
...  

Acyclic monoterpenes constitute a large and highly abundant class of secondary plant metabolites and are, therefore, attractive low-cost raw materials for the chemical industry. To date, numerous biocatalysts for their transformation are known, giving access to highly sought-after monoterpenoids. In view of the high selectivity associated with many of these reactions, the demand for enzymes generating commercially important target molecules is unabated. Here, linalool (de)hydratase-isomerase (Ldi, EC 4.2.1.127) from Castellaniella defragrans was examined for the regio- and stereoselective hydration of the acyclic monoterpene β-myrcene to (S)-(+)-linalool. Expression of the native enzyme in Escherichia coli allowed for identification of bottlenecks limiting enzyme activity, which were investigated by mutating selected residues implied in enzyme assembly and function. Combining these analyses with the recently published 3D structures of Ldi highlighted the precisely coordinated reduction–oxidation state of two cysteine pairs in correct oligomeric assembly and the catalytic mechanism, respectively. Subcellular targeting studies upon fusion of Ldi to different signal sequences revealed the significance of periplasmic localization of the mature enzyme in the heterologous expression host. This study provides biochemical and mechanistic insight into the hydration of β-myrcene, a nonfunctionalized terpene, and emphasizes its potential for access to scarcely available but commercially interesting tertiary alcohols.

2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero

Bamboo is a lightweight and high-strength raw materials that encouraged researchers to investigate and explore, especially in the field of biocomposite and declared as one of the green-technology on the environment as fully accountable as eco-products. This research was to assess the technical feasibility of making single-layer experimental Medium-Density Particleboard panels from the bamboo waste of a three-year-old (Dendrocalamus asper). Waste materials were performed to produce composite materials using epoxy resin (C21H25C105) from a natural treatment by soaking with an average of pH 7.6 level of sea-water. Three different types of MDP produced, i.e., bamboo waste strip MDP (SMDP), bamboo waste chips MDP (CMDP) and bamboo waste mixed strip-chips MDP (MMDP) by following the same process. The experimental panels tested for their physical-mechanical properties according to the procedures defined by ASTM D1037-12. Conclusively, even the present study shows properties of MDP with higher and comparable to other composite materials; further research must be given better attention as potential substitute to be used as hardwood materials, especially in the production, design, and construction usage.


2019 ◽  
Author(s):  
Yu Wang ◽  
Nachuan Yang ◽  
Yi Shuai ◽  
Yunpeng Zhang ◽  
Kanghua Chen

2021 ◽  
Vol 4 (3) ◽  
pp. 51
Author(s):  
Satish Kantipudi ◽  
Daniel Harder ◽  
Sara Bonetti ◽  
Dimitrios Fotiadis ◽  
Jean-Marc Jeckelmann

Heterodimeric amino acid transporters (HATs) are protein complexes composed of two subunits, a heavy and a light subunit belonging to the solute carrier (SLC) families SLC3 and SLC7. HATs transport amino acids and derivatives thereof across the plasma membrane. The human HAT 4F2hc-LAT1 is composed of the type-II membrane N-glycoprotein 4F2hc (SLC3A2) and the L-type amino acid transporter LAT1 (SLC7A5). 4F2hc-LAT1 is medically relevant, and its dysfunction and overexpression are associated with autism and tumor progression. Here, we provide a general applicable protocol on how to screen for the best membrane transport protein-expressing clone in terms of protein amount and function using Pichia pastoris as expression host. Furthermore, we describe an overexpression and purification procedure for the production of the HAT 4F2hc-LAT1. The isolated heterodimeric complex is pure, correctly assembled, stable, binds the substrate L-leucine, and is thus properly folded. Therefore, this Pichia pastoris-derived recombinant human 4F2hc-LAT1 sample can be used for downstream biochemical and biophysical characterizations.


Author(s):  
Charles Oluwaseun Adetunji ◽  
Santwana Palai ◽  
Chika Precious Ekwuabu ◽  
Chukwuebuka Egbuna ◽  
Juliana Bunmi Adetunji ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2910
Author(s):  
Chaoyi Ding ◽  
Chun Liu ◽  
Ligang Zhang ◽  
Di Wu ◽  
Libin Liu

The high cost of development and raw materials have been obstacles to the widespread use of titanium alloys. In the present study, the high-throughput experimental method of diffusion couple combined with CALPHAD calculation was used to design and prepare the low-cost and high-strength Ti-Al-Cr system titanium alloy. The results showed that ultra-fine α phase was obtained in Ti-6Al-10.9Cr alloy designed through the pseudo-spinodal mechanism, and it has a high yield strength of 1437 ± 7 MPa. Furthermore, application of the 3D strength model of Ti-6Al-xCr alloy showed that the strength of the alloy depended on the volume fraction and thickness of the α phase. The large number of α/β interfaces produced by ultra-fine α phase greatly improved the strength of the alloy but limited its ductility. Thus, we have demonstrated that the pseudo-spinodal mechanism combined with high-throughput diffusion couple technology and CALPHAD was an efficient method to design low-cost and high-strength titanium alloys.


2021 ◽  
Author(s):  
Junzhen Ren ◽  
Pengqing Bi ◽  
Jianqi Zhang ◽  
Jiao Liu ◽  
Jingwen Wang ◽  
...  

Abstract Developing photovoltaic materials with simple chemical structures and easy synthesis still remains a major challenge in the industrialization process of organic solar cells (OSCs). Herein, an ester substituted poly(thiophene vinylene) derivative, PTVT-T, was designed and synthesized in very few steps by adopting commercially available raw materials. The ester groups on the thiophene units enable PTVT-T to have a planar and stable conformation. Moreover, PTVT-T presents a wide absorption band and strong aggregation effect in solution, which are the key characteristics needed to realize high performance in non-fullerene-acceptor (NFA)-based OSCs. We then prepared OSCs by blending PTVT-T with three representative fullerene- and NF-based acceptors, PC71BM, IT-4F and BTP-eC9. It was found that PTVT-T can work well with all the acceptors, showing great potential to match new emerging NFAs. Particularly, a remarkable power conversion efficiency of 16.20% is achieved in a PTVT-T:BTP-eC9-based device, which is the highest value among the counterparts based on PTV derivatives. This work demonstrates that PTVT-T shows great potential for the future commercialization of OSCs.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1186
Author(s):  
Carmen S. Favaro-Trindade ◽  
Fernando E. de Matos Junior ◽  
Paula K. Okuro ◽  
João Dias-Ferreira ◽  
Amanda Cano ◽  
...  

Nanoencapsulation via spray cooling (also known as spray chilling and spray congealing) has been used with the aim to improve the functionality, solubility, and protection of drugs; as well as to reduce hygroscopicity; to modify taste and odor to enable oral administration; and many times to achieve a controlled release profile. It is a relatively simple technology, it does not require the use of low-cost solvents (mostly associated to toxicological risk), and it can be applied for lipid raw materials as excipients of oral pharmaceutical formulations. The objective of this work was to revise and discuss the advances of spray cooling technology, with a greater emphasis on the development of lipid micro/nanoparticles to the load of active pharmaceutical ingredients for oral administration.


2016 ◽  
Author(s):  
A. Ribeiro ◽  
C. Vilarinho ◽  
J. Araújo ◽  
J. Carvalho

The increasing of world population, industrialization and global consuming, existing market products existed in the along with diversification of raw materials, are responsible for an exponential increase of wastes. This scenario represents loss of resources and ultimately causes air, soils and water pollution. Therefore, proper waste management is currently one of the major challenges faced by modern societies. Textile industries represents, in Portugal, almost 10% of total productive transforming sector and 19% of total employments in the sector composed by almost 7.000 companies. One of the main environmental problems of textile industries is the production of significant quantities of wastes from its different processing steps. According to the Portuguese Institute of Statistics (INE) these industries produce almost 500.000 tons of wastes each year, with the textile cotton waste (TCW) being the most expressive. It was estimated that 4.000 tons of TCW are produced each year in Portugal. In this work an integrated TCW valorisation procedure was evaluated, firstly by its thermal and energetic valorisation with slow pyrolysis followed by the utilization of biochar by-product, in lead and chromium synthetic wastewater decontamination. Pyrolysis experiments were conducted in a small scale rotating pyrolysis reactor with 0.1 m3 of total capacity. Results of pyrolysis experiments showed the formation of 0,241 m3 of biogas for each kilogram of TCW. Results also demonstrated that the biogas is mostly composed by hydrogen (22%), methane (14 %), carbon monoxide (20%) and carbon dioxide (12%), which represents a total high calorific value of 12.3 MJ/Nm3. Regarding biochar, results of elemental analysis demonstrated a high percentage of carbon driving its use as low cost adsorbent. Adsorption experiments were conducted with lead and chromium synthetic wastewaters (25, 50 and 100 mg L−1) in batch vessels with controlled pH. It was evaluated the behaviour of adsorption capacity and removal rate of each metal during 120 minutes of contact time using 5, 10 and 50 g L−1 of adsorbent dosage. Results indicated high affinity of adsorbent with each tested metal with 78% of removal rate in chromium and 95% in lead experiments. This suggests that biochar from TCW pyrolysis may be appropriated to wastewaters treatment, with high contents of heavy metals and it can be an effective alternative to activated carbon.


2000 ◽  
Vol 15 (1) ◽  
pp. 2-8 ◽  
Author(s):  
N.C. Wagner ◽  
S. Ramaswamy ◽  
U. Tschirner

AbstractA pre-economic feasibility study was undertaken to determine the potential of cereal straw for industrial utilization in Minnesota. Specifically, utilizing straw for pulp and paper manufacture was of interest. The availability of cereal straw fiber supplies at various locations across the state of Minnesota, along with pre-processing issues such as transportation, harvesting, handling, and storage, are discussed and priced. The greatest economic advantage of straw for industrial use appears to be the low cost of the raw material compared to traditional raw materials. This also provides an excellent opportunity for additional income for farmers. The methodology and information provided here should be helpful in evaluating the feasibility of utilizing straw for other industrial purposes in other parts of the world. However, in some Third World countries, long-standing on-farm, traditional uses of cereal straws for fuel, fiber, and animal feed may limit their availability for industrial utilization.


2017 ◽  
Vol 15 (1) ◽  
pp. 332-343 ◽  
Author(s):  
Karolina A. Wojtunik-Kulesza ◽  
Katarzyna Targowska-Duda ◽  
Katarzyna Klimek ◽  
Grażyna Ginalska ◽  
Krzysztof Jóźwiak ◽  
...  

AbstractAlzheimer’s disease (AD) is by far the most prevalent of all known forms of dementia. Despite wide-spread research, the main causes of emergence and development of AD have not been fully recognized. Natural, low-molecular, lipophilic terpenoids constitute an interesting group of secondary plant metabolites, that exert biological activities of possible use in the prevention and treatment of AD. In order to identify secondary metabolites possessing both antioxidant activity and the potential to increase the level of acetylcholine, selected terpenoids have been screened for possible acetylcholinesterase inhibitory activity by use of two methods, namely Marston (chromatographic assay) and Ellman (spectrophotometric assay). In order to describe the interaction between terpenes and AChE active gorge, molecular docking simulations were performed. Additionally, all analyzed terpenes were also evaluated for their cytotoxic properties against two normal cell lines using MTT assay. The obtained results show that: carvone (6), pulegone (8) and γ-terpinene (7) possess desirable AChE inhibitory activity. MTT assay revealed low or lack of cytotoxicity of these metabolites. Thus, among the investigated terpenes, carvone (6), pulegone (8) and y-terpinene (7) can be recognized as compounds with most promising activities in the development of multi-target directed ligands.


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